Japan's economic growth slowed in the last three months of 2017 and missed expectations, preliminary official figures show.

The world's third-largest economy expanded at an annualised rate of 0.5% in the quarter, against analyst forecasts of 0.9%.

But it is still the country's eighth consecutive quarter of growth - the longest streak since the late 1980s.

The GDP figures compare with annualised growth of 2.2% in the previous quarter.

Annualised growth rates represent a value of growth if the quarter-on-previous quarter rate of change were maintained for a full year.

'Positive position'

Despite the disappointing data, there were signs of confidence among Japanese shoppers.

Consumer spending, which accounts for about 60% of Japan's economy, rose by 0.5% compared with the quarter before, against expectations for a rise of 0.4%.

Tokyo-based economist Jesper Koll told the BBC that for the first time in 30 years, the country's economy was in a positive position.

"You've got wages improving, and the quality of jobs is improving, so the overall environment for consumption is now a positive one, while over the last 30 years it was a negative one," said Mr Koll, from WisdomTree asset management company.